1. Field of the Invention
The present invention relates to the use of a platelet aggregation inhibitor and, more particularly, to a platelet aggregation inhibitor whose active ingredient is nattokinase and a supplement food using the same.
2. Description of the Related Art
Previously, nattokinase has been known as a thrombolytic enzyme, and a thrombolytic activity of the nattokinase has been known to be excellent not only for preventing thrombosis but also for treating the thrombosis (Shinsaku Takaoka: Japan Food Science, 39 (9), 55–60, 2000).
The nattokinase is not contained in soybeans, but produced in the course of fermentation when Bacillus natto acts on the soybeans, and further, the nattokinase also contains vitamin K2 as a blood coagulation factor. Therefore, ingestion of natto or Bacillus natto culture extract which contains the nattokinase as a thrombolytic enzyme, for the purpose of preventing thrombosis, means that the vitamin K2 is also ingested simultaneously. Thus, there has been a problem that an effect of the vitamin K-dependent coagulation factor synthesis inhibitor is counteracted. Consequently, a technique for producing Bacillus natto culture extract whose vitamin K2 content is 1 μg/g or less on a dry weight basis has been developed (see Japanese Patent Laid-Open No. 2001-299277).